Posts Tagged AFO

​​​​WalkAide: Helping​​ You Get a Leg Up on Foot Drop

WalkAide is a class II, FDA cleared medical device, designed to improve walking ability in people experiencing foot drop caused by upper motor neuron injuries or conditions such as:

Multiple Sc​​lerosis (MS)​

Stroke (CVA)

Cerebral Palsy (CP)

Incomplete Spinal Cord Injury

Traumatic Brain Injury (TBI)​​

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​Foot Drop or Dropped Foot is a condition caused by weakness or paralysis of the muscles involved in lifting the front part of the foot, which causes a person to drag the toe of the shoe on the ground or slap the foot on the floor.

Foot drop (also known as drop foot) may result from damage to the central nervous system such as stroke, spinal cord injury, traumatic brain injury, cerebral palsy and multiple sclerosis. The WalkAide is designed to assist with the ability to lift the foot for those individuals who have suffered an injury to their central nervous system. The WalkAide is not designed to work with people who have damage to the lower motor neurons/peripheral nerves.​

WalkAide vs. AFO​

Traditionally, foot drop is treated with bracing using an ankle foot orthosis (AFO). The passive treatement offered by AFOs do not promote active use of neuromuscular systems and also limits ankle range of motion. In addition, AFOs can be uncomfortable, bulky, and, if poorly fitted, produce areas of pressure and tissue breakdown. The WalkAide may replace the traditional AFO to re-engage a person’s existing nerve pathways and muscles. Using the WalkAide, in most cases, frees the patient from AFO restrictions.

The recruitment of existing muscles results in reduction of atrophy and walking fatigue – a common side effect of foot bracing. WalkAide users have the freedom to walk with or without footwear, up and down the stairs, and even sidestep.

Advanced Technology; Easy to Use

​​​Invented by a team of researchers at the University of Alberta, WalkAide uses functional electrical stimulation (FES) to restore typical nerve-to-muscle signals in the leg and foot, effectively lifting the foot at the appropriate time. The resulting movement is a smoother, more natural and safer stepping motion. It may allow faster walking for longer distances with less fatigue. In fact, many people who try WalkAide experience immediate and substantial improvement in their walking ability, which increases their mobility, functionality, and overall independence.

​A sophisticated medical device, WalkAide uses advanced tilt sensor technology to analyze the movement of your leg. This tilt sensor adjust the timing of stimulation for every step. The system sends electrical signals or stimulation to the peroneal nerve, which controls movement in your ankle and foot. These gentle electrical impulses activate the muscles to raise your foot at the appropriate time during the step cycle.

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​Although highly-advanced, WalkAide is surprisingly small and easy to use. It consists of a AA battery-operated, single-channel electrical stimulator, two electrodes, and electrode leads. WalkAide is applied directly to the leg — not implanted underneath the skin — which means no surgery is involved. A cuff holds the system comfortably in place, and it can be worn discreetly under most clothing. With the WalkAide’s patented Tilt Sensor technology, most users do not require additional external wiring or remote heel sensors.

​​WalkAide Provides the Advantages not Found in Typical Foot Drop Treamtents :

Customized For Individual Walking Pattern

​WalkAide is not a one size fits all device. Rather, a specially trained medical professional customizes and fits the WalkAide. Using WalkAnalyst, a multifaceted computer software program, the clinician can tailor WalkAide to an individual’s walking pattern for optimal effectiveness.

Exercise Mode for Home Use

​In addition fo walking assistance, the WalkAide system includes a pre-programmable exercise mode that allows a user to exercise his/her muscles while resting for a set period of time as prescribed.​

Objectives: This study aims to investigate the effect of ankle foot orthosis (AFO) on temporospatial parameters, ankle kinematics, and functional ambulation level in patients with stroke.

Patients and methods: Records of 286 adult patients with stroke assessed in the gait and motion analysis laboratory between April 2005 and January 2013 were reviewed. The data of 28 patients (16 males, 12 females; mean age 43.2±15.9 years; range 20 to 72 years) who were analyzed with and without AFO during the same session were selected for the study. Temporospatial parameters (walking speed, cadence, opposite foot contact, double support time, single support time, step time, and step length) and ankle kinematics (ankle dorsiflexion at initial contact and midswing) were measured using the Vicon 512 motion analysis system. The video and medical records of patients were examined to determine their ambulation level according to Functional Ambulation Category.

Results: Walking speed, cadence, and ankle dorsiflexion at initial contact and midswing were significantly increased while walking with AFO compared to walking barefoot (p<0.05). There were significant reduction in step time and significant increase in step length and opposite foot contact with AFO on the affected side (p<0.05). Single support time reduced significantly with AFO on the unaffected side (p<0.05). Functional Ambulation Category score improved significantly with use of AFO (p<0.05).

Conclusion: The use of AFO has positive effects on gait parameters and functional ambulation in patients with stroke.

Like this:

Turbomed Orthotics offers the FS3000 external foot drop brace. The FS3000 brace is a custom-built modular AFO (ankle foot orthosis) made from highly durable thermoplastic. The device attaches to the outside of a patient’s footwear and is easily interchangeable between shoes. The unique design of the FS3000 brace acts as an exoskeleton to the impaired limb, helping to improve the patient’s function without discomfort or rubbing. The FS3000 brace does not prevent ankle plantar flexion or limit dorsi­flexion, making it easier for patients to walk and run on slopes, stairs, and uneven surfaces.

Objective: To compare the effects on walking of Functional Electrical Stimulation (FES) and Ankle Foot Orthoses (AFO) for foot-drop of central neurological origin, assessed in terms of unassisted walking behaviours compared with assisted walking following a period of use (combined-orthotic effects).

Data Synthesis: Seven RCTs were eligible for inclusion. Two of these reported different results from the same trial and another two reported results from different follow up periods so were combined; resulting in five synthesised trials with 815 stroke participants. Meta-analyses of data from the final assessment in each study and three overlapping time-points showed comparable improvements in walking speed over ten metres (p=0.04-0.95), functional exercise capacity (p=0.10-0.31), timed up-and-go (p=0.812 and p=0.539) and perceived mobility (p=0.80) for both interventions.

Conclusion: Data suggest that, in contrast to assumptions that predict FES superiority, AFOs have equally positive combined-orthotic effects as FES on key walking measures for foot-drop caused by stroke. However, further long-term, high-quality RCTs are required. These should focus on measuring the mechanisms-of-action; whether there is translation of improvements in impairment to function, plus detailed reporting of the devices used across diagnoses. Only then can robust clinical recommendations be made.

For 2016, Acor has updated its custom AFO Gauntlets, which are handmade in the company’s Cleveland, OH, facility. Also known as a “Leather Lacer,” the company’s most popular AFO (ankle foot orthosis) gauntlet is the G9210. This particular design comes with a choice of 18 colors of leather, polypropylene reinforcement, and a lining of leather or NeoSponge, a synthetic rubber cushioning material covered with silver impregnated X-Static. The footbed area is now seamless, and Mini-Check antiskid soling is an option. The company has reduced turnaround time to five business days in-house.

1) Within-subject comparison. Impact factor: 2.78
2) Population: community dwelling post stroke at least 6 months prior to study
3) Mode: Functional Electrical Stimulation
4) Parameters: amplitude: pulse width: 1-150 nanosec., frequency/pulse rate: 30 Hz, phase duration: 230 microseconds
5) Protocol: electrodes placed over the common peroneal nerve and anterior tibialis. Treadmill was set at 20-30 km/hr. depending on patient ability
6) Outcome: Use of FES proved to improve obstacle clearance ability in those who have had a stroke, specifically if there is decreased muscular strength involved in the anterior tibialis area. The use of the FES was superior, but not significantly superior, to the use of an AFO.

Based on this article, I would use functional electrical stimulation to aide in decreasing foot drop related fall risk due to decreased obstacle clearance ability. I would not, however, base my decision between FES and an orthotic strictly on this study because the difference in outcome was not significant enough to influence my opinion. I would focus more on specific patient situation and preference when selecting method of control for foot clearance of object.

Like this:

Patient suffered CVA with resultant right sided hemiparesis. Here, he dons a custom molded ankle foot orthosis and is educated about proper donning/doffing, skin care, and wearing schedule. This particular brace is used to enhance clearance of right lower extremity during ambulation as well as provide joint alignment and stability.

In the rehabilitation world, there are a number of approaches to manage the physical sequelae that occur post-stroke. One of those sequelae is foot drop, which is most common among the impairments characteristic of post-stroke patients, and experienced by an estimated 20% of all stroke survivors.1 Since foot drop affects ability to safely ambulate throughout the home and community, retraining the impaired muscles that contribute to foot drop becomes a priority. Lower-extremity bracing is one measure that can be used to manage foot drop. Correctly timing the decision to fit a patient with a brace or other orthosis has been heavily discussed in the literature, and understanding the considerations that can help pinpoint that optimum time are explored in this article.

Multidisciplinary Expertise is Essential

At the Kessler Institute for Rehabilitation, patients affected by stroke are seen for initial bracing evaluations during the inpatient and outpatient phases of recovery. They are also reassessed as needed throughout the continuum of care. For some patients, a brace or orthosis for daily use may be prescribed. In such cases, a team of rehabilitation professionals is called on to participate in the decision-making process.

The team physician leads the decision-making process and is ultimately responsible for determining which orthotic best suits the patient’s needs. The physical therapist assists with the bracing decision-making process by contributing gait analysis expertise. An orthotist designs and fabricates an ankle-foot orthosis (AFO) when prescribed, provides expertise in biomechanical gait principles, and integrates that expertise with orthotic-based materials. The patient/caregiver provides feedback for discussion among the other team members and ultimately makes the decision about bracing based on recommendations made by the team.

Other factors weighed during the decision-making process for bracing include limited insurance or financial restrictions put on custom bracing, limited access to an orthotist, and likelihood of compliance.

Timing Variables

Making the decision about the optimal point in time to fit a patient with an orthosis is multifactorial. This decision can be dependent on discharge disposition with particular regard to whether the patient is discharging to home, and if safety is a primary concern secondary to a lack of ankle control. The level of impairment as well as weakness and instability should be taken into consideration, coupled with any prognostic indicators for a positive return in muscle control.

Many variables can account for how an AFO can improve walking endurance and functional ambulation long-term among patients affected by chronic stroke. For example, the AFO will create ankle joint stability and enhance foot clearance through swing phase of gait. This will alter gait mechanics and ultimately help to enhance the patient’s confidence in their own gait ability. An AFO preserves first ankle rocker with hemiplegic patients and provides a more efficient weight acceptance at initial contact to allow for enhanced double limb support and, thus, increased gait speed.2 Gait efficiency is also an important factor to consider when discussing energy expenditure and a patient’s ability to perform functional ambulation. Dynamic AFOs were shown to decrease energy cost of walking, as demonstrated from the Physiological Cost Index when compared to shoes only with chronic stroke patients.3

Comparing Braces and Orthoses

There are important pros and cons for each type of orthosis, with cost and weight the two most common factors. Also, there are drawbacks generally associated with the use of an orthosis that include compliance secondary to comfort, limited ankle motion, and a relatively fixed position (unless an articulating AFO is prescribed).

Part of the decision about bracing may come down to trade-offs between a customized AFO and an “off the shelf,” prefabricated brace. The advantages each confers are distinct. For example, a custom molded AFO offers the ability to create an optimal fit and provides maximum control of the limb. In contrast, while mass-produced prefabricated orthoses may sacrifice quality of fit and limb control, they can be used as an evaluative tool or a short-term fix during the rehabilitation process.

The conventional double upright AFO is another common bracing solution that may require review by the multidisciplinary team. This design is used when there is significant or fluctuating edema that may constrict the limb and present pressure-related issues with the fit of an AFO. An articulating (hinge) AFO is used to assist with continued dorsiflexion and allow for great ankle ROM. It is not appropriate if spasticity is present, and can be challenging for shoe wear because width is typically wider to accommodate joint of brace.

Carbon composite AFOs are a dynamic bracing option that allow for push-off during third (forefoot) ankle rocker of gait. These AFOs are made to keep the foot up during swing phase, and provide a soft heel strike and stability in stance. This type of brace is contraindicated for patients affected by significant edema, ulcers, and spasticity. Several types of carbon composite AFOs are offered by Allard USA, Rockaway, NJ, including the ToeOFF, ToeOFF Short, BlueROCKER, KiddieROCKER, KiddieGAIT, and Ypsilon. Each brace in this carbon fiber AFO product line is designed to offer specific benefits such as increased rigid orthotic control, size optimized to wearer’s stature, and to accommodate varying levels of spasticity.

Posterior Leaf Spring (PLS) is another common bracing option usually offered as a prefabricated product. The Superior C-90 from AliMed, Dedham, Mass, is an example of this type of brace, and built to provide a full range of plantar and dorsiflexion. The Superior C-90 also provides a thin trim line and allows for eccentric lowering of foot and dorsiflexion for tibial advancement over foot through mid-stance. One drawback to this design, however, is the lack of medial/lateral stability of ankle and poor knee control. It is also contraindicated for patients with spasticity and genu recurvatum or extensor thrust.

Functional Electrical Stimulation is an Option

Orthoses engineered to provide functional electrical stimulation (FES) to the wearer during use can be an alternative to traditional AFOs. The use of FES, particularly for lower extremity bracing, has been associated with increased gait velocity, decreased energy expenditure with gait, and improved gait symmetry. Two manufacturers that provide these devices include Reno, Nevada-based Innovative Neurotronics, which manufactures the WalkAide, and Valencia, Calif-headquartered Bioness, which manufactures the Bioness L300. Among the two products’ distinguishing structural characteristics, the WalkAide has a built-in tilt sensor while the L300 is designed with a heel switch sensor. Both products are considered FES devices, yet the mechanism of action used by each differs slightly.

At Kessler, the Bioness L300 is available for patients to trial. In my experience, and one of the advantages of using the L300, is the result in physiological changes such as increased muscle strength, improved volitional control, and increased joint range of motion. These changes indicate an increased therapeutic effect not associated with the use of traditional AFOs. Another advantage is highlighted in a study by Everaert et al that examined patient preferences for devices and revealed a statistical difference between patients who preferred to use the WalkAide versus an AFO.4 An additional benefit of using FES devices is a purported decrease in spasticity, which further improves the therapeutic effect.

There are some drawbacks associated with the use of an FES device, however, and the most common is cost. Third-party payors often decline coverage for FES devices, so the cost typically falls to the patient. The patient must also tolerate the stimulation so the motor nerve can be activated. Skin irritation is an undesirable side effect, and the wearer’s tolerance must be carefully monitored. Contraindications for these devices include demand-type pacemakers, any cancerous lesion, fractures, or dislocation. Cognitive impairment that could affect ability to use the device is another important consideration. Ultimately, the decision to use a brace as therapeutic treatment for foot drop is a collaboration with one goal: to improve a patient’s ability to safely ambulate and maximize functional independence. PTP

Farris Fakhoury, PT, DPT, has been a physical therapist in the Outpatient Neurologic Gym at Kessler Institute for Rehabilitation for 4 years, and is also the physical therapy lead for the facility’s amputee program. Fakhoury is the physical therapy lead for Kessler’s Amputees Coming Together (ACT) support group as well as for the Bioness program for outpatient services. He earned a bachelor of arts in psychology from Villanova University and a doctor of physical therapy from the joint program of Rutgers University/University of Medicine and Dentistry of New Jersey PT Program in Stratford, NJ. For more information, contactPTProductsEditor@allied360.com.

Rich Klager, PT, DPT, NCS,has been a physical therapist at the Kessler Institute for Rehabilitation in West Orange, NJ, for more than 8 years. His clinical practice experience expands over the Inpatient and Outpatient facilities in the neurologic population. He currently assists with the Outpatient orthotic clinic decision-making process with the Team Physician and Orthotist for patient bracing needs.

After stroke some residual gait deficits can remain and are prevalent. Foot drop is one of the common impairment which affects around 20% of stroke survivors. This impairment is caused by a paresis (total or partial) of the muscles involved in ankle dorsiflexion. This muscle weakness makes the ground clearance problematic during the swing phase of gait. This default can be compensated by ankle foot orthosis (AFO) but also by functional electrical stimulation.

This is an ancient technique that has benefited from recent advances in technology: wireless link, implanted stimulation, replacement of the heel switch by an inclinometer (System Walkaid)… The SEF is effective in improving walking parameters including walk speed but despite these recent technological improvements, it does not show that it is a more effective device than ankle foot orthoses in a recent study [1]. An inertial node combining an accelerometer, a gyroscope and a magnetometer placed on one of the two legs, is used to estimate the continuous walking cycle [2]. This can advantageously replace the switch in the heel to improve reliability to determine when to start or end the stimulation and also allow for example to start the stimulation at any time, including before the heel off the ground. Moreover, this inertial node should also estimate a number of walking parameters including the quality of ankle dorsiflexion and walking type (normal walk but also pass an obstacle, turn around or climbing stairs) and thus to propose an adaptive functional electrical stimulation in an intelligent way.

The purpose of the presentation is to provide an update on the latest clinical studies and develop perspectives brought by the use of inertial nodes coupled with a wireless stimulator to integrate decision algorithms.

SureStep manufactures a variety of products but is primarily known for the SMO (Supra malleolar orthosis) and pediatric AFOs (ankle foot orthosis). The SureStep SMO is meant for patients up to 80 pounds with hypotonic presentations. The purpose is to control the side to side movements of the ankle. The trim lines can be extended longer laterally or medially depending on whether the patient is pronating or supinating. As patients grow older there is a device called the Big Shot that accommodate children and adults weighing over 80 pounds. What makes the SureStep SMO so unique is the dynamic function that the brace allows. It uses compression to create alignment, unique trim-lines to allow freedom of motion where needed, and made from a material that travels together along with the foot.

Controling the Tri-Planar Deformities

This works under compression to maintain stability through midline. In young patients with CMT they can possibly present with a more over pronated foot position because of the low muscle tone (hypotonia) prior to developing a high arch foot presentation. This can been seen in CMT patients who have some symptoms of the disease but have not developed a high arch otherwise known as pes cavus foot. The SMO holds the heel in vertical alignment, giving stability in a coronal plane (side to side) position. An SMO is not necessarily for a patient who has weaknesses pushing up or down the ankle, just poor side-to-side movement.

Improving Stability During Gait

The device is designed to allow for motion to still occur from in and out of the midline position but limits the extremes that the foot would go to, in other words the extreme rolling inward our outward of the ankle. The goal is to improve balance and stability, or limit orthopedic injury. This helps limit out toeing or in toeing as well by improving the position to foot is landing on the ground. Having improved alignment may also utilize remaining strength for dorsiflexion or plantarflexion because the line of pull that these muscles are in has improved line of progression.

Fitting the Device

The trim-lines of the SureStep SMO are designed to be either longer on the lateral border for pronation or medial border for patient who supinate excessively and the orthotist should make the appropriate selection based on the patient’s mechanics. These trim-lines are critical to the successful outcome of this device. Although the SureStep SMO is primarily designed for a younger population as children get older or adults who still have need for such a device the same mechanism of function can be accomplished using the BigShot SMO manufactured by SureStep.

Composite material advances over the past 10 years have improved the design creativity and possibility for clinical orthotists worldwide. In the past, an ankle orthosis required a completely solid and fully encompassing design in order to attain the mechanical control, durability and ultimately the function needed for corrective ankle varus bracing. These devices were essentially plastic shells that created a solid/static environment which was safer than not using a brace at all, but they were also highly problematic with patients complaining of pressure points and a clunky gait. Today we can simulate more natural gait patterns while completely avoiding pressure points.

Controlling the Tri-Planar Deformities

Kinetic Research offers a variety of ankle braces, each with its own character and effect to meet the needs of the user, from the most basic needs to the most complex. For folks that have foot/ankle weakness but have good alignment of their ankle, we offer the Noodle line of AFOs. These are the most dynamic and least restrictive designs for controlling drop foot. When the user has a tight heel cord with mild supination or ankle varus, they become a candidate for a PLS design. When the user has more significant ankle varus he/she becomes a candidate for the ValgaNoodle AFO. The ValgaNoodle offers the highest degree of lateral control that we can provide. It’s important to have a team approach when choosing the type of AFO that will work best for your individual needs, and there is always a trade off between control and mobility. The team is made up of the patient, the orthotist and the physician/therapist, and all have to be involved for the best results. The objective is to “put on as little as possible, but get the job done”.

Improving Stability During Gait

The ValgaNoodle is made specifically for varus control. It’s a highly custom AFO, meaning. That it is not assembled using pre-made components. The creation of a ValgaNoodle begins with a highly skilled orthotist who will evaluate and cast for the device. That attending orthotist will manipulate and control the patient’s foot while he is casting, keeping the ankle in the best position possible to maximize the effect of the finished ValgaNoodle. Evaluations and observations made by the clinical orthotist are then incorporated into a design formulation that will work best for the individual patient. The design details are then determined based on the level of control vs free movement that is needed to maximize the performance of the user. One of the objectives is to keep the ValgaNoodle lightweight and as simple to use as possible. The orthotist will select the device based on the severity of the case, as well as the users lifestyle, activities and footwear.

Fitting the Device

The one common mechanical concept for the ValgaNoodle variations of AFOs is, that they will all have a single medial strut with a floating lateral “reverse T” cuff.

Design options for the footplate:

Flat, in which we match the bottom of the shoe. When we make it in this format, it will usually have a custom foam removable arch support. It offers the least control but because it’s flat, we can make it flexible.

Contoured. This is similar to a UCBL footplate. Our technicians will adjust the cast taken by your orthotist to increase lateral control in a compact way for easy shoe selection.

Contoured with high control. This system goes higher than the UCBL, encompassing the dorsum of the foot, and has a special 3-point strapping system to provide maximum control.